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I would say so I was too tired last night to really dig into some material but after a great night's rest, I really want to dig into some material tonight. I also want to see what I can do with getting a house curve back on it, but I am going to listen the way it is right now for a bit before I make any additional changes.

Quote:

Originally Posted by Scott Simonian

He's got 12dB more ~10hz which in "more subs" talk would be quadruple. I believe Brandon has a pair of dual-opposed SI's currently so that would be equivalent to having sixteen SI's.

Yep, but the good news is the truck is FINALLY back!!! It took me intercepting it Sunday on my way back from ATL, but now I can start scooping the OSB for the shadow wall, as well as some new BB to add the other 4 SI's back in Then I will be back in dangerous territory...

Quote:

Originally Posted by audiovideoholic

Krypto would be sososo happy seeing ported ibs like this!!! I still to this day think about him and his unusual habits and endeavors trying to find his happiness from what subs he had to play with at the time. Nothing was out of the question when trying to dig a little lower and louder only to have his little satellite LCRs drownded out.

While the shadow build is the 6th order BP and this is just a ported IB, I thought about K-Dub several times while constructing this. He tried so hard to get someone to build out some RE designs, and I know for sure right now he is definitely "Subscribed" to this thread

Looking at this again, interesting. I'd be curious to experiment with various low pass points on the rear sub to attempt to further optimize the FR through the modal region, ... and perhaps filling in the crucial 50-80 region.

Having never fully explored blending a mixed alignment system, I'm just not well versed in what you're up against. I would love to examine what transpires upon sealing the vent in the rear, and temporarily employing it as a sealed/IB, then explore fully additive summation across the full band. I've also have zero experience with such a ported IB, and how elements like any type of lossiness, leaks, or internal damping, etc., influence the output, and can those items be attributable to the FR behavior up top? I've no clue, ... anyone?

Obviously, splitting hairs here, as the bottom end of the system is significantly increased, and the FR is very nice, but wth, still curious.

I do plan on messing around a little with low pass filters and whatnot. I wanted to see how the response did full band with both going but since the top end doesn't gain much, I have no issues trying out all kinds of other options. I do want to try full on sealed, and the 5" ports as well, which would seemingly have even more 10hz potential. This is truly uncharted waters just as we have known from the get-go. Even if I am unable to improve from where I am now, I would still say it is quite a success.

Andrew and I were talking last night too, and the peavey has got some serious juice at 2 ohms. This amp is quite the piece for $750....

I've also have zero experience with such a ported IB, and how elements like any type of lossiness, leaks, or internal damping, etc., influence the output, and can those items be attributable to the FR behavior up top? I've no clue, ... anyone?

Yep, but the good news is the truck is FINALLY back!!! It took me intercepting it Sunday on my way back from ATL, but now I can start scooping the OSB for the shadow wall, as well as some new BB to add the other 4 SI's back in Then I will be back in dangerous territory...
While the shadow build is the 6th order BP and this is just a ported IB, I thought about K-Dub several times while constructing this. He tried so hard to get someone to build out some RE designs, and I know for sure right now he is definitely "Subscribed" to this thread

Yay! Great news! Get them other 18's back in the game.

Quote:

Originally Posted by noah katz

Loss/leaks will primarily effect output at port tuning(s).

Yup. This, definitely.

I believe that good internal dampening will reduce effects up high (resonances and such) but most of these are just outside the bandwidth of a subwoofer.

Thanks, I understand that, I didn't make myself entirely clear.
I was curious about any of that potential lossiness, alone, or combined with internal reflections ... negatively affecting the FR he's exhibiting.

Krypto would be sososo happy seeing ported ibs like this!!! I still to this day think about him and his unusual habits and endeavors trying to find his happiness from what subs he had to play with at the time. Nothing was out of the question when trying to dig a little lower and louder only to have his little satellite LCRs drownded out.

So went through some of the big bass scenes last night. This is downright impressive. I am still fine tuning to get the systems gain matched, but right now I am awful close to being there. WOTW and Hulk were absolutely incredible. Underworld super lycan had me worried about the ceiling above my head and caused the PJ lens to shift down. I loved it.

FOTP and Irene was interesting to say the least. I wasn't really sure what I was hearing but there was something that seemed a little off on these two. The bottom end was there, but the whop-whop-whop on the chopper and the barrel-roll on the phoenix seemed to lack a little punch. after doing a little more gain adjustments, I got it all back to what I was hoping though. bottom line is I had the subs just a shade too hot and was missing some of the upper bass that the Danleys aided in supplying by listening at -5. backing off the subs and listening at -2 or so fixed me right up. Same sub level, just more LCR.

All in all, I am mad impressed so far. Now that I do know how to dial it in pretty well, I want to try the other dual 5" ports, and the sealed orientation and graph what each looks like at the LP. After I do that I might try splitting the bandwidth between the two systems and see how that sounds as well. There are just way too many options at my fingertips right now, Lol.

All in all, I am mad impressed so far. Now that I do know how to dial it in pretty well, I want to try the other dual 5" ports, and the sealed orientation and graph what each looks like at the LP. After I do that I might try splitting the bandwidth between the two systems and see how that sounds as well. There are just way too many options at my fingertips right now, Lol.

Dude, from what you've posted so far, leave that s*** alone!! Enjoy it for the behemoth that it is and get back to cranking. Spend a little time with filters/phase and integration and crack a beer or ten and enjoy.

Maybe I'm still missing something, as I'm just stating standard behavior which you can observe in a modeling program that lets you change Ql, like UniBox.

Is there some reason you think this situation wouldn't conform?

Noah,
I understand the impact at tuning freq, I'm curious about the FR up top.
This began with my question here, back in the last post on the previous page.
Beast stated "I didn't get much gain up top regardless of how I set the delay on them." Which, caught my attention ... as I expressed previous curiosity wrt mixed alignment summation.

I referenced "the crucial 50-80 region", and "fully additive summation across the full band", and most importantly; "how elements like any type of lossiness, leaks, or internal damping, etc., influence the output, and can those items be attributable to the FR behavior up top?"

I understand the "less output at tuning freq", my query is wrt the FR up top, 50-80 range.

Maybe that initial question dropping off on the previous page didn't help. We can move on, but I did want to answer you.

Specifically, it's been my theoretical understanding when mixing alignments, one could achieve additive acoustic summation down low (with phase/time adjustment), but broad spectrum additive summation could be problematic. So, I immediately was curious and wanted to rule out an execution error (no offense Beast). Or is this more likely a complex 1/4 wave destructive issue?

----

Quote:

Originally Posted by beastaudio

So went through some of the big bass scenes last night. This is downright impressive. I am still fine tuning to get the systems gain matched, but right now I am awful close to being there. WOTW and Hulk were absolutely incredible. Underworld super lycan had me worried about the ceiling above my head and caused the PJ lens to shift down. I loved it.

FOTP and Irene was interesting to say the least. I wasn't really sure what I was hearing but there was something that seemed a little off on these two. The bottom end was there, but the whop-whop-whop on the chopper and the barrel-roll on the phoenix seemed to lack a little punch. after doing a little more gain adjustments, I got it all back to what I was hoping though. bottom line is I had the subs just a shade too hot and was missing some of the upper bass that the Danleys aided in supplying by listening at -5. backing off the subs and listening at -2 or so fixed me right up. Same sub level, just more LCR.

All in all, I am mad impressed so far. Now that I do know how to dial it in pretty well, I want to try the other dual 5" ports, and the sealed orientation and graph what each looks like at the LP. After I do that I might try splitting the bandwidth between the two systems and see how that sounds as well. There are just way too many options at my fingertips right now, Lol.

Love this, all of it.

I too have reached that masking point, where significant spectral portions a bit higher in freq just aren't prominent enough for adequate bass experience top to bottom.

Congrats, ... and looking forward to your additional thoughts as you progress even further.

Thanks FOH, and Fellas!! It is pretty easy for my to interchange the ports so that will be the first part of the experimental stage. Easy to do, and very quickly reversable if the response is affected negatively.

It should be noted that I have both of these systems running off a single sub out of the 8801, not the sw1 sw2 config that I do have at my disposal. I prefer using the DCX and my own method of phase delay as opposed to the automated Audyssey meshing. FWIW, I have not even used Audyssey at all over the last couple months.

Quote:

Beast stated "I didn't get much gain up top regardless of how I set the delay on them." Which, caught my attention ... as I expressed previous curiosity wrt mixed alignment summation.

Actually completely inversing the polarity to the IB created a very substantial boost up top, but then I lost the boost down low. I would get the slight extension advantage, but no additional spl. The graph I have posted with the polarity normal yielded the smoothest overall response, so I stuck with that When I break the measurement gear back out, I will flip it real quick so you can get an idea of what the differences are.

Beast stated "I didn't get much gain up top regardless of how I set the delay on them." Which, caught my attention ... as I expressed previous curiosity wrt mixed alignment summation.

I referenced "the crucial 50-80 region", and "fully additive summation across the full band", and most importantly; "how elements like any type of lossiness, leaks, or internal damping, etc., influence the output, and can those items be attributable to the FR behavior up top?"

OK got it, though I'm not sure what I'm going to say is any help.

Seems to be that only internal damping could affect 50 - 80 Hz, but not likely much, and that any issues there may be due to shorter wavelengths and interference at those freq both between the subs and mains (what's the XO freq?).

In fact it's evident from the plots that there is destructive interference, as at 60 Hz the summed output is less than the SI's output.

Thanks FOH, and Fellas!! It is pretty easy for my to interchange the ports so that will be the first part of the experimental stage. Easy to do, and very quickly reversable if the response is affected negatively.

It should be noted that I have both of these systems running off a single sub out of the 8801, not the sw1 sw2 config that I do have at my disposal. I prefer using the DCX and my own method of phase delay as opposed to the automated Audyssey meshing. FWIW, I have not even used Audyssey at all over the last couple months.

Good. Are you liking the results so far? I will be doing something similar. Doing mostly external bass management.

In fact it's evident from the plots that there is destructive interference, as at 60 Hz the summed output is less than the SI's output.

This ^ is what I'm talking about.

Is this an rear sub execution issue, or an quarter wave interference issue. Intra-sub, or inter-sub. Alright, I beat that to death ... moving on

Quote:

Originally Posted by beastaudio

I prefer using the DCX and my own method of phase delay as opposed to the automated Audyssey meshing.

Good point, I agree .. the top XT32 two channel time and freq EQ'ing of Audyssey, is a good product for many, but it can be hit or miss. It's powerful, yeah, but the savvy can achieve superior results with outboard dsp, measurement gear, and the chops to use them. Speaking with Seaton about Audyssey and outboard DSP, he suggested I utilize my XT32 in a single sub channel config, on top of my outboard processing. It works well, but it does pay to approach it in a "trust, but verify" manner.

In my experience, Audyssey can really pay dividends in the upper bass, SBIR dominated region, subjectively very appealing. Much higher than that, you shouldn't really be making much EQ'ing changes anyway.

Quote:

Originally Posted by beastaudio

Actually completely inversing the polarity to the IB created a very substantial boost up top, but then I lost the boost down low. I would get the slight extension advantage, but no additional spl. The graph I have posted with the polarity normal yielded the smoothest overall response, so I stuck with that When I break the measurement gear back out, I will flip it real quick so you can get an idea of what the differences are.

Interesting, and would seem to support the general caveats wrt mixed alignments. Distortion aside, smooth response is most important, and that final response you achieved is nice. Phase audibility is often said to be a non-issue. But as you've illustrated, manipulating the time/phase alignment (and low pass freq), all influences the complex acoustic summation ... all roads lead back to final FR, which is essentially what we experience when listening.

Keep us updated with any further changes, this is a very cool project.

Seems to be that only internal damping could affect 50 - 80 Hz, but not likely much, and that any issues there may be due to shorter wavelengths and interference at those freq both between the subs and mains (what's the XO freq?).

In fact it's evident from the plots that there is destructive interference, as at 60 Hz the summed output is less than the SI's output.

Actually with the native response of the IB, it isnt that bad at 60hz. I had to pull down a room mode at around 100hz that took close to a 10dB cut and even with a really high Q it still affected that entire area of the FR. To the best though IMO, as it is still pretty flat all things considered.

Good. Are you liking the results so far? I will be doing something similar. Doing mostly external bass management.

Loving it. we listened to some music last night and it was intense. Moreso than I have experienced in the theater so far. I really want to get those other 4 SI's back in now but I will need more amps for that Haha!!!!

Haha. Well, when you have a drop ceiling overhead, and can lights, it is virtually impossible to knock out every single rattle. Soon as you fix one, another pops up. Putting gratuitous amounts of more insulation up in the drop ceiling space helped tremendously, and as far as walls go, all treatments are french cleated on and secured as best as possible. Really there are no very loud rattles, but certainly there are still some that pop up just about every time I run the system. Only during certain scenes where there is absolutely no content other than the super low stuff does it bother me. I would absolutely love to sheetrock in the ceiling to try and alleviate all that, but there is just too much HVAC that needs to run through that area of the house. There really is no other way around it.

Not really, just been enjoying the setup lately. I have watched a couple of movies, and a few demo disc clips, music, etc and just really like how everything is sounding. I do have some more testing to do but just wanted to sit back for a bit and enjoy where I am currently The RE's really supplement the bottom end, and once the other 4 SI's are back in, I feel like it will be hard to push through to the full shadow build, but I will do it, no worries